The themes of this program-project grant are the molecular biology and genetics of viral carcinogenesis and the relationship of the processes involved in viral carcinogenesis and replication to normal cellular processes. Temin and Panganiban work with retroviruses; Mertz and Lambert with papovaviruses; and Sugden with a human herpesvirus. All of the known viruses involved in human cancer (with the exception of hepatitis C virus), are among those studied by this group of investigators. Temin and Panganiban study avian, murine, bovine, and human retroviruses, Lambert and Mertz study bovine and human papillomavirus and simian virus 40, Sugden studies Epstein-Barr virus, and Loeb studies duck and human hepatitis B viruses. The emphasis of each research program within this program-project grant is as follows: Temin studies the genetics of simple and complex retroviruses. Panganiban concentrates on the proteins of primate retroviruses involved in entrance to and exit from cells. Lambert investigates the proteins involved in control of papillomavirus transcription, replication, and transformation. Mertz studies the viral and cellular proteins that control late transcription of simian virus 40, a TATA-less promoter. Sugden's work is concerned with proteins involved in control of Epstein- Barr virus transcription, replication, and transformation. All of these studies will provide much new information for the understanding of evolution, replication, and transformation by these viruses, which either themselves or whose close relatives are involved in human cancer.